General Operation

Open current module guide

Calculating a substitute diameter

d_R        substitue diameter

c_S        sum of all allowances in shell

For determining the reinforcement of the opening we recommend the following procedure:

The block flange is divided in:

·         a fictitious nozzle with the dimensions:

d_i = Diameter of opening

s_s = fictitious nozzle wall: s_s = a₁

l_s = fictitious nozzle length:

·         and a fictitious reinforcement pad

h = fictitious height of pad:

b = fictitious width of pad:

If the allowable stress of the block flange is lower than the allowable stress of the shell, you have to reduce the reinforcement areas using the ratio of the allowable stresses.

The procedure is the same as recommended for set-on block flanges (s. Set-on block flange / reinforcement ring), whereas as fictitious nozzle wall the value:

Can be used.

Fig. 3a - Set-in reinforcement or block flange

Fig. 3b – Block flange

Fig. 5 - Tubular reinforced opening

Fig. 6 - Extruded opening

Fig. 9 - Calculation scheme for cylindrical shell

Fig. 10 - Calculation scheme for spherical shell

Fig. 11 - Adjacent openings in longitudinal direction of cylinder

Fig. 12 - Adjacent openings in circumferential direction of cylinder or in spherical shells

Fig. 13 - Disc and tubular reinforcement